Firing a Trigger Whenever an Employee is terminated

 Dear All

I am writing a trigger which needs to be fired whenever an employee is terminated in Oracle HRMS E-Bussiness Suite. There is a custom table which will save some data in columns of that particular employee. Problem is that an Exception is being thrown when employee is terminated. I have tried using AFTER UPDATE ON PER_ALL_PEOPLE_F and AFTER UPDATE ON PER_ALL_ASSIGNMENTS_F. I dont want to touch standard tables. I want only how my trigger get fired whenever an employee is terminated.